1. Field of the Invention
The present invention relates to a package structure of an organic electroluminescence (OEL) panel. More particularly, the present invention relates to a package structure of an OEL panel, having the poly solder interconnection arranged in an array structure.
2. Description of Related Art
The OEL device is a device that uses the organic functional materials with the property of spontaneous light-emitting to achieve the displaying effect. According to the different molecular weight of the organic functional materials, it can be categorized into a small molecular organic light emitting device (SM-OLED) and the polymer light-emitting device (PLED).
The OEL device is using two electrodes to hold an organic light emitting material film from both sides. When a proper bias is applied on it, the electric holes will be injected to the anode and the electrons will be injected to the cathode. Due to this externally applied electric field, a voltage difference is produced. This causes carriers to be moved in the film and cause a recombination of electrons and holes, wherein a portion of electron-holes recombine and release energy, which excites the molecules to an excited state as the excited molecules. The excited molecules will release the excited energy, when excited molecules return back to the ground state. A certain portion of the released energy is release via the photons, resulting in emitting light. This is the basic mechanism for the OEL device to emit the light. Since the kind of organic electroluminescence device has the ability to spontaneously emit light, it has many advantages of large viewing angle, fast response time, low driving voltage, full color, and so on, and therefore is expected to be the technology on the planar displaying device for the new generation. Currently, the OEL device has been developed to the stage in practical application. Also and, it can be expected about the application on the color planar displaying device for the next generation, such as the displaying panel for any size, the outdoor post panel, computer, and TV screen. However, comparing with the other displaying technology, the development for OEL device is a little late, the technology have not been completely developed yet. Thus, it is still has many aspects needing further development during the stage to commercialize the OEL displaying device.
Referring to FIG. 1, FIG. 1 is a drawing, schematically illustrating a package structure for the conventional OEL panel. The U.S. Pat. No. 5,747,363 has disclosed a package for an OEL panel, in which the OEL panel mainly includes an OEL panel 100 and a substrate 108. Wherein, the OEL panel 100 has a number of stripe-like anodes 102, an organic light emitting layer 104, and a number of stripe-like cathodes 106. The substrate 108 is implemented with a driving chip 112 and connection pins 110. The pins 110 on the substrate 108 are electrically coupled to the anodes 102 and the cathodes 106 on the OEL panel 100 via an anisotropic conductive film (ACF).
Even though the package structure for the foregoing OEL panel can effectively integrate the driving chip onto the same substrate, it still encounters a restriction of size when a larger size is eventually desired.
Referring to FIG. 2, FIG. 2 is a drawing, schematically illustrating a package structure for another conventional OEL panel. The U.S. Pat. No. 5,693,170 illustrates another package structure for a OEL panel, which includes a several display bricks 200, and a common-use substrate 206 with several bumps 210. Wherein, the displaying bricks 200 have several contact pads 202 near to the surface of the common-use substrate 206. The contact pads 202 are used for the electric connection with the electrodes of anode and cathode on the displaying bricks 200 via, for example, the plugs 204. The common-use substrate 206 is implemented with several contact pads 208 with respect to the contact pads 202. The bumps 210 are implemented between the contact pads 202 and the contact pads 208, so as to have electric connection.
Even though the foregoing package structure for the OEL panel can use several displaying bricks for assembly, so as to achieve the objective of large size, during soldering the contact pads and the bumps, the necessary high temperature in the solder reflowing process would often cause the common-use substrate to be warped. Moreover, the high temperature solder reflowing process would also cause improper affection on the organic light emitting layer in the OEL panel.
An objective of the present invention is to provide a package structure for the OEL panel with less issue on low stress force and better conductivity.
Another objective of the present invention is to provide a package structure for the OEL panel, in which multiple OEL panels can be assembled to the same printed circuit board, so as to breakthrough the restriction of size for the large size.
In accordance with the foregoing and other objectives of the present invention, the invention provides a package structure of the OEL panel, including a printed circuit board, one or multiple OEL panels, and multiple bumps. Wherein, the printed circuit board has multiple solder pads, and at least one OEL panel is implemented on the printed circuit board. The bumps are respectively disposed between the solder pads on the printed circuit board and the poly solder interconnections, so as to have the electric connection for the OEL panel and the printed circuit board.
In the invention, the OEL panel includes a substrate, a first anode, at least one patterned organic light emitting layer, a second electrode, and a poly solder interconnection arranged in an array structure. Wherein, the first electrode is implemented on the substrate. The first electrode includes a driving region and at least one contact region, in which the contact region is protruding out from the driving region. The patterned organic light emitting layer is implemented on the substrate and exposes the contact region. The second electrode is disposed on the organic light emitting layer but not covering the contact region as a design principle. The poly solder interconnection is disposed on the contact region and the second electrode, and is arranged to form an array structure.
In the invention, the driving region of the first electrode on the OEL panel and the second electrode are, for example, the stripe pattern. Also and, the extending direction of the first electrode is, for example, perpendicular to the extending direction of the second electrode.
In the invention, the patterned organic light emitting layer has multiple openings. The openings expose the contact regions, so as to allow the first electrode to be connected out. In addition, the patterned organic light emitting layer includes, for example, stripe patterns, so as to expose the contact regions and be helpful for the first electrode to be connected out.
In the invention, the OEL panel includes, for example, a single-layer panel with a first electrode, an organic light emitting layer, and a second electrode.
In the invention, the OEL panel includes, for example, a multi-layer panel with a first electrode, a hole injection layer, a hole mobile layer, an organic light emitting layer, an electron injection layer, an electron mobile layer and a second electrode.
In the invention, the substrate includes a transparent substrate, such as the glass substrate, the plastic substrate, or soft substrate. The plastic substrate and the soft substrate can include polycarbonate (PC) substrate, polyester (PET) substrate, cyclic olefin copolymer (COC) substrate, metallocene-based cyclic olefin copolymer (mCOC) substrate or thin glass. The first electrode includes, for example, indium tin oxide (ITO), indium zinc oxide (IZO), or aluminum zinc oxide (AZO). The second electrode includes, for example, metal. The poly solder interconnection includes a material with low reflowing temperature, such as silver paste, gold paste, chrome paste, or nickel paste. The printed circuit board includes, for example, a ceramic printed circuit board, and the bumps include, for example, gold stud bump.
In the invention, during the fabricating process for the OEL panel, in addition to the formation of the organic light emitting layer, it can also include formation of a hole injection layer, a hole mobile layer, an electron mobile layer, and an electron injection layer, so as to form a multi-layer structure panel.